New Jersey Democratic gubernatorial candidate Barbara Buono is making official what’s been obvious for years: Her party marches in lockstep with the unions.

Buono, who trails Gov. Chris Christie by 30-plus points in the polls, tapped a top union official as her running-mate for lieutenant governor. Milly Silva, executive vice president of 1199 SEIU, which represents 7,000 nursing-home workers, got her start as a “community organizer” with the far-left activist group ACORN. Her positions read like a typical union wish-list: more public funding and higher minimum wages.

Of course, Jersey Dems have long been in bed with the public-sector unions — quite literally, in the case of ex-Gov. Jon Corzine, whose main squeeze at the time headed the state’s largest public union, creating a troubling conflict of interest. But it’s rare for a candidate, even one trailing as badly as Buono, to advertise the link so blatantly.

In fairness, it’s not like Silva brings absolutely nothing to the table. She’s a female Hispanic, both key Democratic constituencies, and her presence on the ticket likely will energize them and organized labor.

And her story is impressive: The daughter of Puerto Rican-born parents, she grew up in public housing in The Bronx and graduated from Columbia University.

They’ll need whatever help they can get: Fully 37 Garden State Democratic officials have endorsed Republican Christie, including the executive of Silva’s own county.

But her only experience in government is as an advocate, demanding more government spending and protesting Christie’s effort to hold down property taxes.

That’s good for the unions, but Jersey voters may now be looking for someone to look out for them instead.